CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($)	Common Shares and Additional Paid-in Capital Flow-through common shares	Common Shares and Additional Paid-in Capital	Accumulated Deficit	Noncontrolling Interest	Flow-through common shares	Total
Balance at Dec. 31, 2018		$ 1,457,422,000	$ (971,476,000)			$ 485,946,000
Balance (in shares) at Dec. 31, 2018		344,560,000
Increase (Decrease) in Shareholders' Equity
Stock-based compensation		$ 694,000				694,000
Exercise of stock options		$ 544,000				$ 544,000
Exercise of stock options (in shares)		535,000				535,000
Units Issued for cash, net of share issue costs		$ 69,467,000				$ 69,467,000
Units Issued for cash, net of share issue costs (in shares)		53,880,000
Stock issued during the period		$ 1,851,000				1,851,000
Stock issued during the period (in shares)		1,010,000
Shares issued for acquisition of mineral property interests		$ 724,000				724,000
Shares issued for acquisition of mineral property interests (in shares)		354,000
Net loss			(59,747,000)			(59,747,000)
Balance at Dec. 31, 2019		$ 1,530,702,000	(1,031,223,000)			499,479,000
Balance (in shares) at Dec. 31, 2019		400,339,000
Increase (Decrease) in Shareholders' Equity
Stock-based compensation		$ 613,000				613,000
Exercise of stock options		$ 138,000				$ 138,000
Exercise of stock options (in shares)		135,000				135,000
Stock issued during the period	$ 15,478,000				$ 15,478,000
Stock issued during the period (in shares)	13,968,000
Shares issued for debt refinancing		$ (1,875,000)				$ (1,875,000)
Shares issued for debt refinancing (in shares)		2,092,000
Shares issued for acquisition of mineral property interests		$ 70,000				70,000
Shares issued for acquisition of mineral property interests (in shares)		53,000
Net loss			(152,325,000)			(152,325,000)
Balance at Dec. 31, 2020		$ 1,548,876,000	(1,183,548,000)			365,328,000
Balance (in shares) at Dec. 31, 2020		416,587,000
Increase (Decrease) in Shareholders' Equity
Stock-based compensation		$ 837,000				837,000
Units Issued for cash, net of share issue costs		$ 29,875,000				29,875,000
Units Issued for cash, net of share issue costs (in shares)		30,000,000
Stock issued during the period	$ 10,785,000				$ 10,785,000
Stock issued during the period (in shares)	12,601,000
Issuance of equity by subsidiary (Note 20)		$ 25,223,000		$ 14,605,000		39,828,000
Net loss			(56,884,000)	172,000		(56,712,000)
Balance at Dec. 31, 2021		$ 1,615,596,000	$ (1,240,432,000)	$ 14,777,000		$ 389,941,000
Balance (in shares) at Dec. 31, 2021		459,188,000